Ai Yamamoto defeated Erika Takao 6-2 7-5 in the Obihiro-Tokachi 25K round of 32 on carpet. The upset overturned the form book — Erika Takao came in leading the head-to-head 1–0. Ai Yamamoto claimed a first win over Erika Takao in two meetings, narrowing the head-to-head to 1–1.
| Date | Tournament | Round | Surface | Winner | Score |
|---|---|---|---|---|---|
| 2009-09-07 | Noto 25K | R16 | carpet | Erika Takao | 6-2 5-7 6-1 |